Ether acid esters of higher alcohols



25 It must'have a good solvent power for the orditiciz'er. In doing so, I have created a new class 2 alcohol esterifled by an etherlfled azihd .resistlys i hydrolysis and saponiiication. It is emical O 4.0 inert, and being aiarge molecule, it has little mo Bro (Bro O o A 4o vapor tension, while at the same timei it happens 7 7 that thesubstances here under cons! eration are liquids or soft plastics having physical properties wlherem ang fi gfl g ggg suitable for plasticization. The fact that the 3923; 7 45 molecule carries an ether group and an ester 45 reamed M... 1, 19a 2,109,947

urnnn Acm ns'rnas or menu emotions @layton 01m North, Charleston, w. Va., asslgnor, by mesne assignments, to Margaret R. North,- Charleston, W. Va. I

- No Drawing. Application January 27, 11934,

, Serlal No. 708,687

12 Claims. (on. zoo-10s) This invention relates to anew class of estate an, undesirable extent. Further these esters are of ether acids, useful as plasticizers and to methmore or low susceptible to hydrolysis, reverting ods of preparing such esters wherein an ether into their component acids and alcohols. Apmonocarboxylic acid, containing one or more parently the presence or a plurality of ester 5 other groups, is esterifled with a primary monogroups, or of branched chains, rendersthe esters .5 hydric alcohol of relatively high molecular more susceptible to this and to other. decomposiweight, containing between 6and 18 carbon atoms tions such a susceptibility is objectionable in a in a straight chain; all as more fullyhereinafter plasticlzer. It is frequently encountered in polyset forth and as claimed. I esters, such as areobtained'from dibasic acids 1 In order to properly plasticize various coating and polyhydric alcohols, 10 and film-forming materials, such as cellulose ni- Simply using either an acid or alcohol of high trate, cellulose acetate and other cellulose esters molecular weight or of complex structure to raise and others or synthetic and natural resins, such the boiling point of an ester, does not of itself materials and the plasticizer must be mutually solve the problems arising in the prepsrationoi l5 miscible over-a range of temperat r n Other hood, commercial plasticizers. The vapor tension conditions. Further, the plasticizer must remain is more important than the sheer boiling'point Un han d in th c atinss films 0n xp sme' while stability, or permanence, is vital. any deto air if they are to be sumciently permanent for composition, however slight, is undesirable; it commercial utilization. It the plasticizer is 'disleads to loss of miscibility, accelerated decomposipated or decomposed, the coatings or films besition, etc; 20 come brittle or otherwise deteriorated I have found that it is necessary to correlate A satisfactory plasticizer for general use must the acid and alcohol radicles and to provide sufcomply with certain exacting requirements; reficient other linkages to secure the proper perquirements being to a certain extent conflicting. manence and balance of properties in the plasum'rso STATES PATENT orrios nary run of plastic material; it must not have of ether-ester compounds, which are advantaany substantial solubility in water and ordinary geousos plasticizers in the commercial arts; they I liquids; it must not be dissipated on exposure having high solvent power, I to the air or, in other words, it must have a low Th present ether-esters are characterized by 0 vapor tension and it should be as chemically in-. cont z-v'a but one ester group and two or three art as possible resisting attack by acids, alkalies th 'g u a, all in the acid part of the ester, and miscellaneous chemicals. In the present inand Mug {1 mg of branched aliphatic chains in vention these requirements are met by providing the m ym 0f me g t tt part r bodies of a certain structure: a long chain northe an aliphatic straight h in mal alcohol esterifled by an acid with 'a'shorter containing between-6 and 18 carbon atoms. such 35 Barbell chain and carrying ether m- For esters m be remotes by the following i'orstereochemical, and other reasonaya long chain w By varying the R1 and R: and them and n variety of the ma m 4 as indicated and within the range given, I may The various common esters or 'ether or therharms desimd wmblnaesters. particularly those of relatively low molecv on 01 rroperties (misfit!!! v, vanor rres ure. .50 ular weight or of simple structure, are'mostly 1 etc.) need 1 6 given plas i P :1- volatile. While'some ofthemhave reiativ'elyhigh ns. celluloseester, e c" for mm-61 Y boilingvpoints, nevertheless, their vapor tension W m p of the v ri esters Within at ordinary temperaturesis substantial, and when; the abov cl ss are siv n p thin films are exposed to the atmosphere, it i r esters m y be P p from a variety 5; sumcientto cause-{dissipation by evaporation to 0t ether-mono-carboxylic acids and primary group rendersit miscible with pyroxylin and a monohydric alcohols. The following acids are typical:

1. n butoxy acetic acid HgC-(CH -O[(CH O-] CH COOH The first acid is a mono-ether; the next three acids, di-ethers and the last acid, a tri-ether. They are illustrative of the ether-acids here employed to produce the new class of ether-ester plasticizers represented by the following formula:

wherein R is an alkyl group, R: is an ethylene group, R1 represents alkylene and phenylene groups, Re is a long chain alkyl radical, having a straight unbroken chain of CH2 groups and containing between 6 and 18 carbon atoms derived from a primary alcohol and m is l to 2. Variations in R1 are shown in the three di-ethers, it being respectively --CH2--, --CeH4-- and CH2CH2-. That is, R1 maybe phenylene or alkylene; both phenylene and (CH2); specifically shown as illustrations of R1; the a: being shown as 1 or 2.

By varying the length of the alkylene groups and the number of ether groups, as shown ante, a series of ether-ester plasticizers may be obtained; the :0 being varied in the several alkylene groups shown for purposes of illustration. Further illustrations are given post and in some of. them longer alkylene chains are shown, particularly in the terminal alkyl group, to wit, R. Such ether-esters may be also represented by the following formula:

wherein m is 0 to 2, n is 4 to 16 and wherein R3 and R1 are alkylene groups. In the alkylene group R3, forming a part of the terminal alkyl R, sometimes a short alkyl side chain is permissible. For instance, beta-n-propyl-beta-mcthyl-ethoxy acetic acid may be used. The short side chain in that acid is clearly shown in its structural formula which is as follows:

being Likewise, a simple ring (phenylene, etc.) is permissible as R3. (See the use of cresoxy acetic acid, given post.)

These acids may all be prepared by the reaction of primary alcohols with metals, as for example sodium, to produce first sodium alcoholates which are subsequently reacted with halogenated acids. The mono-ether acids of class 1, of which normal butoxy acetic acid is a typical example, may be prepared as follows: About 23 grams of freshly cut metallic sodium are slowly and cautiously added to about 450 cc. anhydrous normal butanol contained in a suitable flask equipped with stirrer and reflux condenser and cooled to about 20 C.

When the sodium has-all dissolved, a solution oi about 47.5 grams monochloracetic acid in about 50 cc. anhydrous butanol is slowly added, the temperature being maintained between 20 and 30 C. After the initial reaction is over, the mixture is heated to the refluxing temperature (about 110 C.) for about minutes. The unreacted butanol is then removed by steam distillation and the water solution acidified by means of hydrochloric acid and cooled to zero degrees. The butoxy acetic acid is separated in the usual manner (weight of crude about 59.2 grams) and distilled in vacuo. The main fraction boils between about 139 and 144 C. at about 26 mm. pressure. The yield is about 3'7 grams. The boiling point at normal pressure is about 232.3 to 234.1 C.

The diand tri-ether acids included in Classes 2, 3, 4 and 5 may be prepared by the methods outlined by Palomaa 8: Slitonen, Berichte, vol. 63 (1930) pages 3117-3120 inclusive. Cresoxy acetic acid is described in Beilstein, Third Edition, vol. 2, page 750.

The ether acids, so prepared, may be esterified with an appropriate monohydric alcohol of the type specified ante. Various higher alcohols, that is, those having a relatively high molecular weight, are appropriate and may be used.

By higher alcohols I allude to those alcohols beginning with normal hexanol CH1(CH2)4CH2OH and extending to and including octadecanol CH3(CH2)16CH2OH. My preferred alcohol 01 this group is dodecanol (1) which is also described as normal dodecyl alcohol CEI3(CH2)10CH2OH, vide Beilstein, 1918, vol. 1, page 428. This alcohol is also known as lauryl alcohol. Other typical alcohols which are all described in Beilstein, vol. 1, are normal tetradecyl alcohol, normal hexadecyl alcohol, normal decyl alcohol, normal octyl alcohol and octadecanol.

The following list gives the above alcohols and their formula in relation to the generic structure of the resulting ester:

1 no] HO-CHz-(CE) ic -CH3 These alcohols are the formula:

yrs

'.had ceased.

excess acid together with a small the low boiling esters HO-CH2 (CH2) n-CH3 wherein n is 4 to16.

In the preparation of my esters Iemploy either the technical dodecyl alcohol'or the mixture of alcohols resulting from the reduction of simple esters such as methyl or ethyl of the fatty acids from cocoanut oil. This reduction yields a mixture of alcohols which vary in constitution from hexanol to octadecanol.

The dodecyl ester of beta-n-butoxy-ethoxy acetic acid may be prepared as follows: 1 mol. of technical dodecanol, commercially known as lauryl alcohol, is mixed with 1% mols of betan-butoxy-ethoxy acetic acid in a suitable flask and 1 cc. concentrated sulfuric acid added. The mixture is heated in an oil bath at 120 C. under reduced pressure bling has ceased, which is usually about four hours. The liquid is then transferred to a Claisen distilling flask and approximately 5 grams of dry calcium carbonate added to neutralize any sulfuric acid remaining. It is then distilled in vacuo in the usual manner. The excess butoxy-ethoxy acetic acid distills over in the neighborhood of 160 C. at a pressure of 5 millimeters. The main fraction distills between 207-246" C. at a pressure of 4 to 6 millimeters.

A mixture of esters may be prepared by starting with the mixture of alcohols resulting from the reduction of cocoanut oil fatty acids as above mentioned. This mixture-is technically known as Lorol. In this experiment I employed betan-butoxy-ethoxy acetic acid. 744 grams of lorol and 880 grams of butoxy-ethoxy acetic acid were mixed and 2 cc. concentrated sulfuric acid added in a suitable flask which was placed in an oil bath heatedto 120 C. Reduced pressure wasapplied (approximately 20 millimeters) and heating was continued for The material was then transferred to a Claisen distilling flask, about 10 grams dry calcium carbonate added and vacuum distillation was performed in the usual manner. The percentage of came over in the beginning. The main fraction, however, distilled between 207-270 C. at 4 millimeters. The main fraction was 1100 grams and liquid.

The dodecanol ester of cresoxy acetic acid was prepared as follows: 88 grams of vacuum distilled cresoxy acetic acid were mixed with 130 grams of technical, normal dodecyl alcohol and A cc. concentrated sulfuric acid added. This was placed in a suitable flask and heated under reduced pressure (approximately 20 millimeters) for 5 hours at 120 C. in an oil bath. The product was placed in a Claisen flask, an excess of dry barium carbonate added and the product vacuum distilled in the usual manner. The first fraction included everything coming over up-to 240 C. at 18 millimeters. The main fraction distilled from 243- as follows:

. tic acid previously prepared (20 millimeters) until all bubethoxy acetic acid is of particular'value 'I'he product is a pale yellow liquid. This ester has the following formula:

' gen atom,

about 10 hours until all bubbling consisted of a pale yellow The dodecanol or lauryl ester of beta-n-propylbeta-methyl-ethoxy acetic acid may be prepared 186 grams of technical lauryl alcohol, derived from cocoanut oil, were mixed with 199 grams of beta-n-propyl-beta-methyl-ethoxy aceafter the method of Palomaa and Siitonen from commercial 2 methyl pentanol and chloracetic acid, and A cc. concentrated sulfuric acid added. The mixture was heated in a suitable flask in an oil bath at 120 C. under reduced pressure (20 millimeters) for approximately 5 hours until all bubbling had ceased. It was then transferred to a distilling'flask and a small excess'of barium carbonate added and the product distilled in vacuo. The main fracmeters and amounted to 214 grams. This was a pale yellow liquid.

All the above esters are excellent solvents and plasticizers for nitrocellulose and may be used in the preparation of nitrocellulose lacquers and plastics. The dodecanol ester of beta-n-butoxybecause of its high resistance to ultra violet light. This finds application in the preparation of white lacquers for refrigerator purposes and the like. I

These esters are also very useful as plasticizers for cellulose acetate, cellulose ethers and for various natural and synthetic resins. I

It will be readily apparent that many ether acid esters of higher alcohols can be prepared. For example, in the preparation of ether acids themselves much variation is possible. A wide variety of primary alcohols may be employed and various halogenated acids will react with the sodium alcoholates. The halogen may be present to the extent ofione or more atoms in the halogenated acid and its position in the molecule while important is not required to be in anydeflnite place. When the halogen acid used to prepare the ether acid contains more than one halofor instance,'an acid containing two halogen atoms, the ether acid produced in that case will have the following formula:

The sodium alcoholates may be prepared either from metallic sodium or from caustic soda.

In effecting esterification I have found it convenient to use the method described but any other method suitable for the preparation of esters may also be employed and I am not to be limited as to the method of preparing my ether acid esters and I believe myself entitled to all similar compounds which come within the spirit and contemplation of my invention.

etc.,

wherein n is 4 to 16 and R1 is a group selected from the class consisting of lower alkylene groups and phenylene groups.

4. As new products useful as plasticizers, etc., the esters having the following formula wherein a is 1 to 2.

, 5. As new products useful as plasticizers, etc., the esters having the following formula:

wherein m is l to 2, Hi represents a lower allcylene group and Re is a long alkyl radical, having a straight unbroken chain of CH: groups and containing between 6 and 18 carbon atoms, derived from a primary alcohol.

6. As new products useful in plasticizers, etc., the esters having the following formula:

wherein R1 is a lower alkylene group, R3 is a group selected from the class consisting of a lower alkylene group and a phenylene group, and n is from 4 to 16.

7. The ester having the following formula said ester being the dodecanol ester 'of cresoxy acetic acid.

8. As new products useful as plasticizers, etc., the esters having the following formula:

whereinmis1to2and::is1to2,saidesters being free of side chains.

9. As new products useful as plasticizers, etc., the ether-esters having the following formula wherein R1 represents a lower alkylene group, R3

represents a member of the class consisting of alkylene and phenylene groups, 1 is O to 2 and nis4to16.

10. As new products useful as plasticizers, etc., the esters having the following formula carbon group of the class consisting of a lower alkylene group.

. 11. As new products useful as plasticizers, etc., the dodecanol esters of a di-ether carboxylic acid having the following formula:

HJC (CHI)I O 'CIHFO R] I OH wherein R4 is a group of the class consisting of CH2, CgHi and phenylene.

12. As new products useful as plasticizers, the dodecanol esters of ether acids having the following formula:

wherein m is 0 to 2.

CLAYTON OLIN NORTH.

wherein n is 4 to 16 and R1 is a divalent hydro- 

